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<br />Individualized. As applied to drainage estimates, indicates studies for specific <br />drainages that include considerations for possible local influences. In the <br />sense of applications to specific basins, it is commonly implied that information <br />obtained from a generalized study will be processed and result in specific <br />drainage-averaged values. <br /> <br />Local Storm. A storm event restricted in time and space. Precipitation rarely <br />exceed~ 6 hr in duration and the area covered by precipitation is less than <br />500 mi. Frequently local storms will last only 1 or 2 hr and precipitation will <br />occur over only 100 or 200 mi 2. Precipitation in local storms is considered <br />isolated from general-storm rainfall. <br /> <br />Module. A self-contained unit of a complex procedure. <br /> <br />Orographic Separation Line (OSL). A line separating regions where there are <br />different orographic effects on precipitation. In one region, the nonorographic <br />region, the only factors producing precipitation are atmospheric forces. In <br />contrast, in the orographic region, precipitation results from a combination of <br />atmospheric forces and lifting of air by terrain. <br /> <br />Probable Kaxi8Um Precipitation (PKP). Theoretically the greatest deptb of <br />precipitation for a given duration that is physically possible over a given size <br />storm area at a particular geographic location at a certain time of the year. <br /> <br />Spatial Distribution. The geographic distribution of PMP for the storm area <br />according to a storm with an idealized pattern. <br /> <br />Storm Centered. A characteristic of a storm that is always determined in <br />relation to the maximum observed value in the storm as compared to the same <br />factor for some other duration and area of the storm. For example, a storm- <br />centered depth-area ratio relates the average depth over some specific isohyetal <br />area of the storm that encloses the center of the storm to the amount at the <br />storm center. <br /> <br />Temporal Distribution. The order in which incremental PMP amounts are arranged <br />within the PMP storm. The time distribution within the local storm period is <br />provided. The distribution of PMP values within the general storm is not <br />discussed. <br /> <br />Total Storm Area and Total Storm Duration. The largest area <br />duration for which depth-area-duration data are available <br />rainfalls of record (sec. 2.2). <br /> <br />size and longes t <br />for major storm <br /> <br />Within Storm. A storm characteristic determined when values of various <br />parameters are required to be from the same storm. For example, a 6-/24-hr ratio <br />where the values for each duration are always selected as the maximum values for <br />the particular duration in the ~ storm (see also Among Storm). <br /> <br />Several additional terms that are used only in chapter 7 are defined at the <br />beginning of that chapter. <br /> <br />6 <br />